谁能帮我把英语作文改错解析一下!

AfewmonthslaterreturningtotheU.S.fromGermany,ItookpartinacollegecourseinFrench.SinceIhavelearnedtospeakGermanwellinGermany,Ithoughtitmightbeinterestedtobeginstudyinganotherlanguage.InthefirstclassateacheraskedustodoapronunciationexerciseinithewouldsayawordortwoinFrench.Theneachstudentwoulddotheirbesttocopy.Whenitgottomine,hekepthavingmesaymorewords,andIfinallyaskedhimforwhy.“Ifinditgreatfun,”heexplained.“In25yearsofteachingatschool,it'sthefirsttimethatIheardanAmericanspeakFrenchbyaGermanaccent.”1monthslaterreturning/monthsafterreturning2.Ihavelearned/Ihadlearned3.beinterestedto/beinterestingto4.ateacherasked/theteacherasked5.inithe/inwhichhe6.dotheirbest/dohisbest7.gottomine/gottome8.askedhimforwhy/去掉for9.Iheard/Ihaveheard10.byaGermanaccent/withaGermanaccent我需要你们帮我回答一下为什么这么改,这么改的原因是什么